| MCKINNEY, Texas
MCKINNEY, Texas Republican presidential contender Rick Santorum, a day after his stunning sweep of nominating contests in three states, scrambled in Texas on Wednesday to round up the support and money he needs to take on well-financed and well-organized rival Mitt Romney.
After winning in Minnesota, Missouri and Colorado on Tuesday, Santorum sought to build on his momentum, addressing Texas pastors, donors and activists with the loosely organized conservative Tea Party movement.
"Nobody ever thinks I can win anything," Santorum told about 600 people at a meeting with Christian pastors at the Bella Donna Chapel in McKinney, Texas. "The gift of being underestimated is a great gift."
Santorum, a former U.S. senator from Pennsylvania and a staunch social conservative, became the first Republican White House hopeful to win four of the state-by-state contests to pick a nominee to oppose Democratic President Barack Obama in the November 6 election.
His sweep on Tuesday raised new questions about presumed front-runner Romney, who holds strong organizational and financial advantages over Santorum and the other Republican candidates but has yet to prove he can win over conservatives in the party who see him as too moderate.
Before his triumphs on Tuesday, Santorum had been dismissed as an also-ran in the race, having finished in the back of the pack in recent primaries and caucuses and trailing badly in the money race. But he now has won in one more state than Romney, who has three victories to date.
In 2011, Santorum raised $2.2 million, according to year-end filings. Romney raised $56.8 million.
Santorum is the latest in a series of rivals seen as the conservative alternative to Romney, who needs to refocus his campaign to re-establish himself as the favorite for the nomination.
Foster Friess, the main backer of Santorum's "Red White and Blue" so-called Super PAC, said he expected more funding after Santorum's victories on Tuesday.
"I think as a result of last night there seems to be a nice flow of money, suddenly people realize that he's got a shot," said Friess, who was photographed standing beside Santorum as he gave his victory speech in Missouri on Tuesday night.
Political action committees (PACs) are groups with great clout in U.S. politics that are legally separate from candidates. They spend money to back candidates and causes they support, often unleashing negative advertising.
'FAITH AND FAMILY'
His surge comes at a perfect time for Santorum, a devout Roman Catholic who speaks often on the campaign trail about his seven children and is known for Christian conservative stances such as fierce opposition to abortion rights and gay marriage.
With signs of improvement in the U.S. economy, social issues have taken on more prominence in the 2012 campaign, helped by recent headlines.
"He's the only person who is passionate about conservatism. He's not afraid to talk about faith and family," said Noah Jackson, who attended Santorum's $250 per person fundraiser at a tony Dallas-area country club.
Republican contenders Romney, Santorum and Newt Gingrich accuse Obama of waging war on religion because of positions including a rule requiring health insurance plans, including those offered by Catholic hospitals, to provide birth control.
Republican U.S. House of Representatives Speaker John Boehner joined the fray on Wednesday by saying the rule amounted to an attack on religious freedom and promising that Congress will act, if needed, to stop it.
A U.S. appeals court on Tuesday ruled that California's ban on gay marriage violated the U.S. Constitution. Santorum, Romney and Gingrich all denounced the decision.
The Susan B. Komen for the Cure breast cancer charity's decision, later revoked, to stop funding for Planned Parenthood, also kept social issues in the public eye. Planned Parenthood is a women's health network that provides birth control, abortions and other services.
With Romney targeted as a "flip-flopper" for abandoning earlier moderate positions on healthcare and abortion, supporters credit Santorum for his unchanging positions.
"In a time when there is much cynicism about the authenticity of candidates, he has that box checked," Republican strategist Keith Appell said of Santorum.
Gingrich, the former House speaker who looked strong after winning the South Carolina primary on January 21, has slumped since then. Struggling after campaign missteps and fierce attacks from Romney, he was not on the ballot in Missouri and was crushed in the other two states on Tuesday.
The next major Republican nominating contests are the Arizona and Michigan primaries on February 28, while Maine wraps up its caucuses this Saturday.
Critics portray Romney as a cold-hearted capitalist who cannot connect with voters because of his privileged upbringing as the son of a governor and corporate chief executive, and the personal fortune estimated at $270 million he amassed running a firm that bought - and sometimes broke up - troubled companies.
Some Christian conservatives are also wary of Romney because of his Mormon religion.
Santorum touts his background as the grandson of a coal miner, and says his economic policies would help generate jobs for working Americans.
(Additional reporting by Steve Holland in Denver, and Alina Selyukh, Bill Trott, Susan Heavey, and Patricia Zengerle in Washington; Writing by Patricia Zengerle; Editing by Alistair Bell and Will Dunham)